1. Technical Field
The present invention relates to a DC electric motor control device that controls drive of a DC electric motor for actuating an object.
2. Related Art
For example, Japanese Unexamined Patent Publication Nos. 8-91239 and 2005-318791 disclose DC electric motor control devices that control the drive of the DC electric motor.
In the control device disclosed in Japanese Unexamined Patent Publication No. 8-91239, a motor driving circuit constructed by four FETs is driven to control a normal rotation or a reverse rotation of the DC electric motor, thereby assisting a steering force of a steering wheel of a vehicle. When turn-on of an ignition key is detected, breakdown of a motor current detector is determined based on a current passed through the DC electric motor, which is detected by the motor current detector, and a current that is predicted in applying a voltage to the DC electric motor for a predetermined time.
In the control device disclosed in Japanese Unexamined Patent Publication No. 2005-318791, a motor driving circuit constructed by two relays and a FET is driven to control the normal rotation or the reverse rotation of the DC electric motor, thereby actuating an opening and closing body of the vehicle. In the case that drive control of the DC electric motor is stopped in a period during which the drive current is not passed through the DC electric motor, a test micro current is passed between the DC electric motor and the relay to turn on and off the relay, and the breakdown of the DC electric motor, the FET, or the relay is determined based on a detection result of the voltage between the relay and the FET.
In the opening and closing bodies, such as a rear hatch and a slide door of the vehicle, it is necessary to instantaneously switch the opening and closing bodies to an opening operation for the purpose of safety when a person or an object is caught in the opening and closing bodies during a closing operation. In the case that the opening and closing bodies fall freely in a closing direction due to the breakdown while the opening and closing bodies are being opened, it is necessary to close the opening and closing bodies against a gravitational force. Therefore, it is advantageous to securely reversely rotate the rotating direction of the DC electric motor while the DC electric motor is being driven.